1. Field of the Invention
The present invention relates generally to head cleaners and image forming apparatuses, and more particularly to a head cleaner cleaning the nozzle face of a liquid droplet ejecting head that ejects liquid droplets and an image forming apparatus including the head cleaner.
2. Description of the Related Art
Some of the image forming apparatuses, such as printers, facsimile machines, copiers, and multifunction apparatuses having printer, facsimile, and copier functions, include a liquid droplet ejecting head that ejects ink that is a recording liquid from fine nozzles, and form (record) images using the head.
In such inkjet recording apparatuses, ink droplets are ejected from fine ejection openings. Accordingly, clogging of ejection openings may be caused by increased ink viscosity or ink adhesion due to dryness, or bubbles generated in the ink, thus causing an ejection deficiency. A recovery device for recovering and maintaining the normal state of the ink ejection function is provided in order to prevent such ejection deficiencies.
As a recovery method using such a recovery device, for instance, one or an appropriate combination of two or more of: a maintenance recovery method that repairs ejection openings by filling a recording head with ink using pressuring means in the case of an ejection deficiency due to bubbles generated in the ejection openings during recording; a maintenance recovery method that performs preliminary ejection (flushing) in preparation for an increase in ink viscosity or ink adhesion due to natural evaporation of ink in ejection openings; and a maintenance recovery method that wipes off ink droplets or dust adhering to an ejection opening face, is employed.
As a head cleaner having a blade for wiping the nozzle face of a head, a head cleaner with blade cleaning means for cleaning a blade is known. For instance, Japanese Laid-Open Patent Application No. 2000-141672 (Document 1) discloses a head cleaning technique that wipes off ink, adhering to the wedge-shaped end of a blade at the time of performing wiping, with a wiper cleaning member by providing the wiper cleaning member to an ink cartridge mounted on a carrier.
Further, according to the technique disclosed in Japanese Laid-Open Patent Application No. 9-314852 (Document 2), a wiper member and a wiper cleaning member for cleaning the wiper member are provided at an interval so that ink adhering to the wiper member is discharged through the space between the wiper member and the wiper cleaning member, and after the end of wiping, the wiper member is deflected in the direction opposite to the wiping direction so that the wiper cleaning member moves ink adhering to the side of the wiper member to the wiper cleaning member.
With respect to recent image forming apparatuses using ink, use of pigment ink using organic pigment or carbon black as colorant has been studied or put into practice in order to enable high quality printing on plain paper. Unlike dye, however, pigment has no water solubility. Therefore, normally, pigment is mixed into water together with dispersant so as to be employed as aqueous ink where the pigment is stably dispersed into water by dispersing.
In general, such pigment ink has higher viscosity than dye ink, thus causing the problem of high viscosity. That is, there is a problem in that in the case of wiping off high viscosity ink adhering to the nozzle face of a recording head, the ink cannot be wiped off sufficiently by merely wiping with a blade having a wedge-shaped end as disclosed in Document 1.
On the other hand, in the case of performing wiping using a blade shaped to have a top face as disclosed in Document 2, it was observed that high viscosity ink did not flow to the side of the blade as early as low viscosity ink, so that the ink remained adhered to the top face and the side face of the blade.
When the next wiping operation is performed with the ink thus adhered, this is likely to result in incomplete wiping, thus causing a problem in that nozzle “drop-out” or jetting curving occurs.
Further, in the conventional head cleaner, a blade is cleaned immediately after a nozzle face is wiped. Accordingly, ink may adhere to the blade before wiping of the nozzle face is started, thus resulting in a problem in that wiping cannot be performed in a clean state.